A pn junction diode is a basic semiconductor device that controls the flow of electric current in a circuit. In forward bias condition, current is constant until certain voltage is reached. Investigation of the static characteristics of a npn junction transistor in common. However, unlike a resistor, a diode does not behave linearly with respect to the applied voltage as the diode has an exponential currentvoltage iv relationship.
Class 12 cbse board pn junction diode learnnext offers animated video lessons with neatly explained examples, study material, free ncert solutions, exercises and tests. To study the v i characteristics of p n junction in reverse bias, class 12, physics experiment. Physics project for class 12 on effect of pn junction on half. The pn junction diode is a twoterminal device, which is formed when one side of the pn junction diode is made with ptype and doped with the ntype material. The flowing of these electrons from emitter to collector forms the current flow in the. Physics of semiconductor devices pn junction depletion width. Iv characteristics pn junction diode theory a semiconductor pn junction diode is a two terminal electronic device that allows current in only one direction. Pn junction one of the crucial keys to solid state electronics is the nature of the pn junction. Physics of semiconductor devices pn junction depletion width problem a silicon pn diode has a doping of n d 81015 1 cm3 and n a 210 16 1 cm3. In the simpler case of a very highly asymmetric junction for example.
Normally the voltage is taken along the xaxis and current along yaxis. Pn junctions consist of two semiconductor regions of opposite type. A pn junction is the metallurgical boundary between the n and pregions of a semiconductor crystal. Coed school kolar road bhoapl department of physics project report investigatoryproject on pn junction and diodes project report submitted by govind patel submitted to mrs ratna hajela registerationno. What happens when we join ptype and ntype semiconductors. Feb 01, 2018 to study the v i characteristics of p n junction in reverse bias, class 12, physics experiment. Avalanche multiplication impact ionization of electronhole pairs tunneling through the junction zener breakdown at high doping concentrations, identical to that of tunneling in a metalsemiconductor junction. To determine the focal length of athe given concave mirror by uv method. Vi characteristics of pn junction diode electronics post. An npn transistor, a three volt battery, a 30 volt battery, two high resistance. It is composed of semiconductor material with at least three terminals for connection to an external circuit. When one side of an intrinsic semiconductor is doped with acceptor i. As a leading global manufacturer of crushing, grinding and mining equipments, we offer advanced, reasonable solutions for any sizereduction requirements including, physics project for class 12 on effect of pn junction on half way rectifier, quarry, aggregate, and different kinds of minerals. Plot a graph with reverse voltage along x axis and reverse current along y axis.
Definition ptype semiconductor is suitably joined to ntype semiconductor,to conduct surface is called pn junction. To draw the iv characteristics of a pn junction diode in forward. The charge on the left of the junction must be balanced by the charge on the right side of the junction. To study the characteristics of a common emitter npn. When ptype and ntype materials are placed in contact with each other, the junction behaves very differently than either type of material alone. Physics lab manualncert solutions class 12 physics sample papers. When you take a block of silicon and dope part of it with a trivalent impurity and the other part with a pentavalent impurity, a boundary called the pn junction is formed between the resulting ptype and ntype portions. The pn junction solidstate device theory electronics. N junction acts as a closed switch when it is forward biased, i. Approximate solution using the full depletion approximation a abrupt pn junction an easy way to derive the depletion layer widths in a pn diode is to treat it as a combination of two schottky diodes, one with an ntype semiconductor and an other with a ptype. What are the depletion width in the nregion, the depletion width in the pregion, and the builtin potential at 300k.
The manual outlines 12 experiments and instructors will. The pside or the positive side of the semiconductor has an excess of holes and the nside or the negative side has an excess of electrons. To study the characteristics of a common emitter npn or pnp. A voltage or current applied to one pair of the transistors terminals changes the current through another pair of. The pn junction is a versatile element, which can be used as a. Chapter 4 pn junctions a pn junction is present in every semiconductor device.
Please refer laboratory manual class xi ncert experiment3. Silicon a single silicon atom consists of fourteen negatively. To study the characteristic of a common emitter npn or pnp transistor and to. Voltampere vi characteristics of a pn junction or semiconductor diode is the curve between voltage across the junction and the current through the circuit. Whether you are going to work in mnc or going to work with usual private firms, it all depends here.
How a pn junction formed in a diode engineering tutorial. Pn junction doide pn junction condensed matter physics. Working of pn junction diode with biasing, characteristics. Jan, 2015 pn junction diode characteristics lab expriment 1. Physics practical class 12 for board examination 2019 20 byjus. This portion of an npn bjt is just like a pn junction. To draw the iv characteristic curve for a pn junction in forward bias and. A ptype material consists of silicon atoms and trivalent impurity atoms such as. This potential difference can alter the flow of majority carriers, so that the pn junction can be used as an opportunity for the diffusion of. To study the factor affecting the rate of loss of heat of a liquid. Initially, at the metallurgical junction, there is a very large density gradient in both the electron and hole concentrations. Chapter 5 spring 2003 ee lecture 10, slide 2 ntype ptype. Jan 23, 2015 npn transistor is one of the bipolar junction transistor bjt types. A the nend is connected to the positive terminal of the battery done clear.
It is the most essential and the basic building block of the electronic device. Repeat the same procedure for the remaining 12 circuits as in fig. Here, majority carriers from both sides move away from the junction and thus no current flows through the junction. Physics practical class 12 find out more about the cbse physics practical class 12 syllabus and the other experiments that you need to focus on. Vi characteristics of pn junction diode in 3biasing modes. Liquid junction potentials occur at the boundary between. Read on to know the key preparation tips to excel in your cbse class 12 physics practical exams. Apparatus an npn transistor, a three volt battery, a 30 volt battery, two high resistance rheostats, one 03 volt voltmeter, one 030 volt voltmeter, one 050. Class 12 cbse board pn junction diode videos, ncert. When the ntype semiconductor and ptype semiconductor materials are first joined together a very large density gradient exists between both sides of the pn junction. Class12 cbse board pn junction diode learnnext offers animated video lessons with neatly explained examples, study material, free ncert solutions, exercises and tests.
The pn junction is the root for semiconductor diodes. To study the characteristics of a common emitter npn or. Pn junction doide free download as powerpoint presentation. The junction can extend unequally into the n and p regions depending on the relative doping. Cbse ncert notes class 12 physics semiconductor electronics. The graph shows the reverse vi characteristics of the given pn junction diode. Only a small leakage current flows in the reverse voltage bias case. Class 12, physics experiment,to study the vi characteristics curve of p n junction in forward bias. Working of pn junction diode if an external potential is applied to the terminals of pn junction, it will alter the potential between the p and nregions. It generally shows the relation between bias voltage and current of a diode.
To draw the i v characteristic curves of a pn junction in forward bias and. As usual, base junction input junction is forward biased and collector junction output junction is reverse biased. To study the characteristics of a common emitter npn or pnp transistor and to find out the values of current and voltage gains. Sep 10, 2016 pn junction and zener diode 12 class project. The npn transistor consists of two ntype semiconductor materials and they are separated by a thin layer of ptype semiconductor. Get information about tamil nadu board class 12 physics practical. Liquid junction potentials occur at the boundary between two solutions that have different ionic compositionsexist for all reference electrodes that are separated from sample solution by frit, or some other type of electrolytic contact interfaceto prevent bulk mixing of the reference electrode electrolyte with the sample solution. Jan 21, 2019 vi characteristics of pn junction diode. Experiment 15 to draw the i v characteristic curve of pn junction in. Npn transistor circuit working, characteristics, applications. Such junctions show a pronounced rectifying behavior. A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power.
Apr 05, 2019 working of pn junction diode if an external potential is applied to the terminals of pn junction, it will alter the potential between the p and nregions. The pnjunction is the root for semiconductor diodes. The pn junction is the fundamental building block of the electronic age. To study the effect of detergent on surface tension by observing capillary rise. Class 12 physics semiconductor electronics characteristics of a pn junction diode there are two types of characteristics forward characteristics and reverse characteristics. To study dissipation of energy of a simple pendulum by plotting a graph between square of amplitude and time. To draw the iv characteristic curve for a pn junction in forward bias and reverse bias.
Questions you should be able to answer by the end of todays lecture. Physics practical class 12 important physics practicals for class 12th board. By exploring the electrical properties of silicon, it is possible to acquire an understanding of the inner workings of the pn junction. A pn junction diode is one of the simplest semiconductor devices around, and which has the characteristic of passing current in only one direction only. The recombination at the junction allows battery current to flow through the pn junction diode. Semiconductor physics semiconductors and diodessemiconductors. Chapter 4 pn junctions university of california, berkeley. Cbse physics practical class 12 lab manual learn cbse. Download tamil nadu board class 12 physics practical experiments pdf.
The diode is firmed by doping a semiconductor like silicon or germanium with. Experiment 16 the pn junction introduction in this experiment on the physics of the pn junction, a determination is made of both the universal constant ek i. This potential difference can alter the flow of majority carriers, so that the pn junction can be used as an opportunity for the diffusion of electrons and holes. We consider a step junction the doping concentration is uniform in each region and there is an abrupt doping change at the junction. Physics practical class 12 all study guide at one place. It acts as an open circuit when it is reversed biased, i. Npn transistor is one of the bipolar junction transistor bjt types. Semiconductor, silicon, pn junction, forward bias, reverse bias, diode. They are also called pn diodes in analogy with vacuum diodes. Physics projects for class 12 gurukul technical institute. It has a positive p side and a negative n side created by adding impurities to. Or, in terms of the conduction 2 as defined in the figure above, the conduction angle characterizes the fraction of a period that the diode is on. Coed school kolar road bhoapl department of physics project report investigatoryproject on pn junction and diodes project report submitted by govind patel submitted to mrs ratna hajela. Octavian florescu 2 the pn junction diode schematic diagram.
Here the majority charge carriers are the electrons. The boltzmann approximation is to say that the resulting current being small compared with the components of this current, we consider that we are still in quasi equilibrium and therefore that the currents equation is still valid by replacing v bi by v. A pn junction is an interface or a boundary between two semiconductor material types, namely the ptype and the ntype, inside a semiconductor. The pn junction biasing the pn junction the diode trouble shooting. Forward bias current flows reverse bias no current flow.
The pn junction is the basis for diodes, certain transistors, solar cells, and other devices. Jul 06, 2016 when you take a block of silicon and dope part of it with a trivalent impurity and the other part with a pentavalent impurity, a boundary called the pn junction is formed between the resulting ptype and ntype portions. A very small current will made at the junction due to the movement of minority charge carriers across the junction. Pn junction underbiasing 14 boltzmanns approximation.
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